AT-58
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Inspections Before Trouble DiagnosisUCS002CX
A/T FLUID CHECK
Fluid Leakage and Fluid Level Check
Inspect for fluid leakage and check the fluid level. Refer to AT - 1 3 , "Checking A/T Fluid" .
Fluid Condition Check
Inspect the fluid condition.
STALL TEST
Stall Test Procedure
1. Inspect the amount of engine oil. Replenish the engine oil if necessary.
2. Drive for about 10 minutes to warm up the vehicle so that the A/
T fluid temperature is 50 to 80°C (122 to 176°F). Inspect the
amount of ATF. Replenish if necessary.
3. Securely engage the parking brake so that the tires do not turn.
4. Engine start, apply foot brake, and place selector lever in “D”
position.
5. While holding down the foot brake, gradually press down the
accelerator pedal.
6. Quickly read off the stall speed, then quickly remove your foot
from the accelerator pedal.
CAUTION:
Do not hold down the accelerator pedal for more than 5 sec-
onds during this test.
7. Move the selector lever to the “N” position.
8. Cool down the ATF.
Fluid condition Conceivable Cause Required Operation
Varnished (viscous
varnish state)Clutch, brake
scorchedReplace the ATF and check the A/T
main unit and the vehicle for mal-
functions (wire harnesses, cooler
pipes, etc.)
Milky white or
cloudyWater in the fluidReplace the ATF and check for
places where water is getting in.
Large amount of
metal powder mixed
inUnusual wear of
sliding parts within
A/TReplace the ATF and check for
improper operation of the A/T.
SAT6 3 8A
SAT6 4 7B
SCIA1224E
SAT5 1 4G
TROUBLE DIAGNOSIS
AT-59
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
CAUTION:
Run the engine at idle for at least one minute.
Judgement of Stall Test
O: Stall speed within standard value position
H: Stall speed higher than standard value
L: Stall speed lower than standard value
Stall test standard value position
LINE PRESSURE TEST
Line Pressure Test Port
Line Pressure Test Procedure
1. Inspect the amount of engine oil and replenish if necessary.
2. Drive the car for about 10 minutes to warm it up so that the ATF reaches in range of 50 to 80°C (122 to
176°F), then inspect the amount of ATF and replenish if necessary.
NOTE:
The automatic fluid temperature rises in range of 50 to 80°C (122 to 176°F) during 10 minutes of
driving.Stall speed: 2,500 - 2,800 rpm
Selector lever position
Expected problem location
DR
Stall rotation HO
Forward brake
Forward one-way clutch
1st one-way clutch
3rd one-way clutch
OH
Reverse brake
LL
Engine and torque converter one-way clutch
HH
Line pressure low
Does not shift-up D position 1 → 2 Slipping in 2nd, 3rd, 4th gears Direct clutch slippage
Does not shift-up D position 2 → 3 Slipping in 3rd, 4th, 5th gears High & low reverse clutch slippage
Does not shift-up D position 3 → 4 Slipping in 4th, 5th gears Input clutch slippage
Does not shift-up D position 4 → 5 Slipping in 5th gear Front brake slippage
SCIA1291E
AT-60
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
3. After warming up remove the oil pressure detection plug and
install the oil pressure gauge [ST2505S001(J34301-C)].
CAUTION:
When using the oil pressure gauge, be sure to use the O-
ring attached to the oil pressure detection plug.
4. Securely engage the parking brake so that the tires do not turn.
5. Start the engine, then measure the line pressure at both idle and
the stall speed.
CAUTION:
Keep the brake pedal pressed all the way down during
measurement.
When measuring the line pressure at the stall speed,
refer to AT-5 8, "
STALL TEST" .
6. After the measurements are complete, install the oil pressure
detection plug and tighten to the regulation torque below.
CAUTION:
Do not reuse the O-ring.
Line Pressure
SCIA0504E
SCIA1224E
:7.3 N·m (0.74 kg-m, 65 in-lb)SAT4 9 3G
Engine speedLine pressure [kPa (kg/cm
2 , psi)]
R position D position
At idle speed 392 - 441 (4.0 - 4.5, 57 - 64) 373 - 422 (3.8 - 4.3, 54 - 61)
At stall speed 1,700 - 1,890 (17.3 - 19.3, 247 - 274) 1,310 - 1,500 (13.3 - 15.3, 190 - 218)
TROUBLE DIAGNOSIS
AT-61
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
Judgement of Line Pressure Test
ROAD TEST
Description
The road test inspects overall performance of the A/T and analyzes possible malfunction causes.
The road test is carried out in the following three stages.
1. Check before engine is started. Refer to AT - 6 2
.
2. Check at idle. Refer to AT- 6 2
.
3. Cruise test
Inspect all the items from Part 1 to Part 3. Refer to AT- 6 3 , AT- 6 5 , AT- 6 6 .
Before beginning the road test, check the test procedure and inspection items.
Test all inspection items until the symptom is uncovered. Diagnose NG items when all road tests are com-
plete.
Judgement Possible cause
Idle speedLow for all positions
(P, R, N, D)Possible causes include malfunctions in the pressure supply system and low oil pump output.
For example
Oil pump wear
Pressure regulator valve or plug sticking or spring fatigue
Oil strainer oil pump pressure regulator valve passage oil leak
Engine idle speed too low
Only low for a spe-
cific positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
HighPossible causes include a sensor malfunction or malfunction in the line pressure adjustment func-
tion.
For example
Accelerator pedal position signal malfunction
ATF temperature sensor malfunction
Line pressure solenoid malfunction (sticking in “OFF” state, filter clog, cut line)
Pressure regulator valve or plug sticking
Stall speedOil pressure does
not rise higher than
the oil pressure for
idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment function.
For example
Accelerator pedal position signal malfunction
TCM breakdown
Line pressure solenoid malfunction (shorting, sticking in“ ON” state)
Pressure regulator valve or plug sticking
Pilot valve sticking or pilot filter clogged
The pressure rises,
but does not enter
the standard posi-
tion.Possible causes include malfunctions in the pressure supply system and malfunction in the pres-
sure adjustment function.
For example
Accelerator pedal position signal malfunction
Line pressure solenoid malfunction (sticking, filter clog)
Pressure regulator valve or plug sticking
Pilot valve sticking or pilot filter clogged
Only low for a spe-
cific positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
TROUBLE DIAGNOSIS
AT-63
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
4. CHECK “N” POSITION FUNCTIONS
1. Start the engine.
2. Move selector lever to “N” position.
3. Release the parking brake.
Does vehicle move forward or backward?
YES >> Enter a check mark at “Vehicle moves in “N” position” on the diagnostics worksheet, then continue
the road test.
NO >> GO TO 5.
5. CHECK SHIFT SHOCK
1. Engage the brake.
2. Move selector lever to “D” position.
When the transmission is shifted from
“N” to “D”, is there an excessive shock?
YES >> Enter a check mark at “Large shock when shifted from N to D” on the diagnostics worksheet, then
continue the road test.
NO >> GO TO 6.
6. CHECK “R” POSITION FUNCTIONS
1. Engage the brake.
2. Move selector lever to “R” position.
3. Disengage the brake for 4 to 5 seconds.
Does the vehicle creep backward?
YES >> GO TO 7.
NO >> Enter a check mark at “Vehicle does not creep backward in R position” on the diagnostics work-
sheet, then continue the road test.
7. CHECK “D” POSITION FUNCTIONS
Inspect whether the vehicle moves forward when the transmission is put into the “D” position.
Does the vehicle creep forward in the
“D” positions?
YES >> Go to AT- 6 3 , "Cruise Test - Part 1" , AT- 6 5 , "Cruise Test - Part 2" , and AT- 6 6 , "Cruise Test - Part
3" .
NO >> Enter a check mark at “Vehicle does not move forward in D positions” on the diagnostics work-
sheet, then continue the road test.
Cruise Test - Part 1UCS002D0
1. CHECK STARTING OUT FROM D1
1. Drive the vehicle for about 10 minutes to warm up the engine oil and ATF.
Appropriate temperature for the ATF: 50 - 80°C (122 - 176°F)
2. Park the vehicle on a level surface.
3. Move selector lever to “P” position.
4. Start the engine.
5. Move selector lever to “D” position.
6. Press the accelerator pedal about half way down to accelerate the vehicle.
With CONSULT-II
Read off the gear positions.
Starts from D1?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle cannot be started from D1” on the diagnostics worksheet, then
continue the road test.
TROUBLE DIAGNOSIS
AT-75
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
22
Slips/Will
Not
EngageWhen “D” position,
remains in 5th gear.ON vehicle1. Fluid level and stateAT- 5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5
,
AT- 1 5 1
4. Line pressure testAT- 5 9
5. CAN communication lineAT- 1 0 3
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Front brake (brake band)AT- 2 7 38. Input clutchAT- 2 9 5
9. Gear systemAT- 2 6 1
10. High and low reverse clutchAT- 3 0 5
23Vehicle cannot be
started from D
1 .
Refer toAT- 2 0 3 , "
Vehi-
cle Cannot Be Started
From D1" .ON vehicle1. Fluid level and stateAT- 5 8
2. Accelerator pedal position sensorAT- 1 2 9
3. Line pressure testAT- 5 9
4. CAN communication lineAT- 1 0 3
5. Control valve with TCMAT- 2 4 1
OFF vehicle6. Torque converterAT- 2 7 3
7. Oil pump assemblyAT- 2 9 0
8. 3rd one-way clutchAT- 2 9 2
9. 1st one-way clutchAT- 3 0 0
10. Gear systemAT- 2 6 1
11. Reverse brakeAT- 2 7 3
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 8
, AT-1 9 .)AT- 2 7 3
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
24Does not lock-up.
Refer to AT- 2 1 5 , "A/T
Does Not Perform
Lock-up" .ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Engine speed signalAT- 11 5
4. Turbine revolution sensorAT- 1 3 4
5. Torque converter clutch solenoid valveAT- 11 8
6. CAN communication lineAT- 1 0 3
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 39. Oil pump assemblyAT- 2 9 0
No. Items Symptom Condition Diagnostic ItemReference
page
AT-76
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
25
Slips/Will
Not
engageDoes not hold lock-up
condition.
Refer toAT- 2 1 7 , "A/T
Does Not Hold Lock-
up Condition" .ON vehicle1. Fluid level and stateAT-5 8
2. Line pressure testAT-5 9
3. Engine speed signalAT - 11 5
4. Turbine revolution sensorAT- 1 3 4
5. Torque converter clutch solenoid valveAT - 11 8
6. CAN communication lineAT- 1 0 3
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 39. Oil pump assemblyAT- 2 9 0
26Lock-up is not
released.
Refer toAT- 2 1 9 ,
"Lock-up Is Not
Released" .ON vehicle1. Fluid level and stateAT-5 8
2. Line pressure testAT-5 9
3. Engine speed signalAT - 11 5
4. Turbine revolution sensorAT- 1 3 4
5. Torque converter clutch solenoid valveAT - 11 8
6. CAN communication lineAT- 1 0 3
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 39. Oil pump assemblyAT- 2 9 0
27No shock at all or the
clutch slips when
vehicle changes
speed D
1 → D2 . ON vehicle1. Fluid level and stateAT-5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
4. CAN communication lineAT- 1 0 3
5. Line pressure testAT-5 9
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Torque converterAT- 2 7 3
8. Oil pump assemblyAT- 2 9 0
9. 3rd one-way clutchAT- 2 9 2
10. Gear systemAT- 2 6 1
11. Direct clutchAT- 3 0 7
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 8
, AT- 1 9
.)AT- 2 7 3
No. Items Symptom Condition Diagnostic ItemReference
page
AT-78
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
30
Slips/Will
Not
engageNo shock at all or the
clutch slips when
vehicle changes
speed D
4 → D5 .ON vehicle1. Fluid level and stateAT-5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
5. CAN communication lineAT- 1 0 3
6. Line pressure testAT-5 9
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 3
9. Oil pump assemblyAT- 2 9 0
10. Front brake (brake band)AT- 2 7 3
11. Input clutchAT- 2 9 5
12. Gear systemAT- 2 6 1
13. High and low reverse clutchAT- 3 0 5
31When you press the
accelerator pedal and
shift speed D5 → D4
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT-5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
5. CAN communication lineAT- 1 0 3
6. Line pressure testAT-5 9
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 3
9. Oil pump assemblyAT- 2 9 0
10. Input clutchAT- 2 9 5
11. Gear systemAT- 2 6 1
12. High and low reverse clutchAT- 3 0 5
13. Direct clutchAT- 3 0 7
No. Items Symptom Condition Diagnostic ItemReference
page